| 摘要 |
PROBLEM TO BE SOLVED: To drive a plurality of ultrasonic motors, using a common driver. SOLUTION: A primary coil L1 of a transformer T is connected to a high-frequency voltage-generating source Vac of an AC power supply 11a, to output a high-frequency voltage Vu from a secondary coil L0 to piezoelectric elements C1, C2. Each of the piezoelectric elements C1, C2, provided on the stator of the ultrasonic motor, is connected in parallel with the secondary coil, and reactance circuits B1(W), B2(W) are each connected in series to each piezoelectric element. One of the reactance circuits consists of a coil L and a capacitor C, connected in parallel with each other. As a result, the circuits can be simplified, and the cost of a control circuit can be lowered because each resonance circuit of the piezoelectric elements can be operated independently, simply by changing the frequency of the common AC voltage generating means. |
